The Valkyr has been developed as a private venture by Vickers Defence Systems, in association with Beherman-Demoen of Belgium which built the BDX (4 × 4) APC.

Vickers was responsible for research, development and construction of the prototypes based on the initial Beherman-Demoen BDX Mk II design. There are two basic variants of Valkyr which differ only in roof height, the higher roofed vehicle being used for roles demanding maximum internal volume (for example, APC), and the lower roofed version as a Fire Support Vehicle.

A prototype low roof FSV was shown at the 1982 British Army Equipment Exhibition. A preproduction high roof APC was shown at the 1984 exhibition and a Fire Support Vehicle with a two-man 90 mm Cockerill turret was demonstrated at the firepower display. At the 1986 Exhibition an internal security version of the Valkyr APC was exhibited and in 1988 one was configured as a VIP transport vehicle.

The Valkyr has been designed specifically to form the basis of a vehicle family fulfilling a variety of roles as a personnel carrier, fire support vehicle and internal security vehicle.

In addition to extensive trials in Belgium and the United Kingdom the Valkyr has also been tested in Brunei and Oman. Kuwait ordered two vehicles for use in the IS role which were completed in late 1988.

The basic monocoque hull in both versions of the Valkyr is of all-welded high-hardness steel armour.

A high level of protection is available against a wide range of weapons, varying from 7.62 mm armour-piercing projectiles over the frontal arc and 7.62 mm ball over the remainder, up to M1 Garand armour-piercing at any range and any angle of attack (including the roof). Additional protection against armour-piercing rounds can be provided by a layer of applique armour, which in the event of penetration acts as a spall liner.

The hull is also protected from shell splinters from 155 mm howitzer projectiles. The armoured glass windscreen and vision blocks afford similar protection, while the underside of the hull gives protection against anti-personnel mines due to its special shaping and armour. In the event of an explosion, the front wings of the vehicle are designed to blow off, dissipating the force of the blast.

The driver sits centrally at the front of the vehicle. He has access to the troop compartment through a gangway on the left side of the hull.

On the APC a commander's cupola is fitted on the left side of the body between the front wheel arch and side door. A variety of cupolas is offered with various vision and weapon systems.

Access to the crew compartment is through two large rear-opening doors, with a side door on the left for the commander and driver. Stores may be loaded through a door on the right, which also acts as an emergency exit. Vision blocks are fitted above the side door and in each rear door. Weapon firing ports can be fitted to suit the user's needs. The fire support vehicle has a single rear door and additional doors in the left and right sides.

The engine compartment is to the rear of the driver on the right side with the air inlet and outlet louvres in the roof and the exhaust pipe running alongside the upper part of the hull, on the right side. The power pack is fully enclosed by noise absorption panels. A PTO at the front of the engine provides hydraulic power for brake and steering actuation, fan operation and brake cooling oil circulation.

A two-stage air cleaner is fitted. Large particles of dust and sand are removed by the cyclonic first stage while a dry filter element removes the remainder. An electrical restriction indicator provides a visual warning to the driver when the filter element needs replacing.

The Detroit Diesel 4-53T engine is water-cooled. The coolant flows through a gill-type radiator mounted horizontally above the engine. Air is drawn through the radiator by a hydraulically driven mixed flow fan. A second gill-type radiator is mounted below the coolant radiator and cools the axle/brake oil. The transmission is cooled by air drawn through vents in the rear over the engine transmission casings and expelled through the roof.

A Kidde-Graviner FIREWIRE fire detection system is fitted around the engine/transmission area, with a manually operated extinguishing system.

The engine is directly coupled to an Allison Transmission Division AT-545 fully automatic gearbox with four forward and one reverse gears and a two-speed transfer case. For road use the rear-wheel drive is normally engaged, with the four-wheel drive being selected on soft ground as required. To improve traction an automatic locking differential is fitted to the rear axle and a manually lockable differential to the front axle.

The engine and transmission are all located within the armoured hull for maximum protection against disabling damage. Drive is provided to the hubs through the constant velocity joints on the front and universal joints on the rear. Hub reduction units are employed on all wheels.

Fully independent suspension is fitted all round and each wheel is located on double wishbones with variable rate coil springs and coaxial telescopic dampers. The steering is power-assisted rack and pinion.

The brakes are of the oil-immersed multiple disc type, which means that heat generated by braking is dispersed into the oil which is continually cycled through a remote cooler.

The foot brake operates hydraulically on all four wheels, with full power assistance. A dual hydraulic circuit, split vertically into front and rear axle systems, ensures braking capability in the event of either circuit failing. Hydraulic accumulators incorporated into the brake circuit provide a reserve of power to stop the vehicle even with the engine disabled. The mechanical handbrake operates on the rear wheels.

The large tyres of the Valkyr reduce ground pressure and improve traction on soft ground. They are also able to propel the vehicle in water as the Valkyr is fully amphibious. Speed may be increased by the addition of a water propulsion system which can be mounted at the rear of the hull.

Valkyr as an APC can carry eight fully equipped troops plus the driver and commander/gunner. Ample storage is provided behind the seats for light anti-tank weapons, ammunition, a 48-hour survival kit appropriate for NATO operations, water and spare fuel. The seats can be lifted to allow large loads to be carried and two standard NATO pallets may be accommodated easily in the hull. The Valkyr FSV has been designed to accept a complete range of turret and weapons including:

• One-man turret with twin 7.62 mm machine guns

• One-man turret with 7.62 mm and 12.7 mm machine guns

• Two-man turret with 7.62 mm machine gun, 20 mm cannon and 60 mm gun/mortar

• Two-man turret with 90 mm gun

• One-man anti-aircraft turret with twin 20 mm cannon

In addition six crew members can be carried.

Optional equipment includes an air conditioning system, an NBC system, passive night vision equipment, alternative protection levels and run-flat tyres

In addition to being used as an APC and FSV the Valkyr can be used for a wide range of other roles including anti-tank with ATGW, close support, recovery, workshop, state vehicle, command post, field ambulance, 81 mm mortar carrier and internal security vehicle. For the last role a variety of equipment can be fitted including a barricade removal device, grenade launchers, a public address system, Molotov cocktail protection, a roof-mounted machine gun, a water cannon and armoured shutters. At the 1988 British Army Equipment Exhibition, Valkyr was shown configured as a VIP transport with the interior by Rolls-Royce, Mulliner Park Ward.